Random assignment of patients to a group is best described as

Random assignment of patients to a group is best described as

• A. A process that ensures equal numbers in each group
• B. Assigns participants to groups based on investigator preference
• C. The constitution of groups in a study such that all subjects have an equal chance of being assigned to any group or condition
• D. Allocation is not blinded

Answer: (C)

Random assignment means each subject has an equal chance of ending up in any group. This equal probability helps prevent selection bias and distributes both known and unknown confounding factors across groups, making comparisons between groups more valid. It isn’t about guaranteeing exact equal numbers in every group, though that can happen by chance, nor is it about investigator preference, which would introduce bias. Allocation being blinded or not is a separate issue from how subjects are assigned; randomization can be done with blinding or without it.

Random assignment means each subject has an equal chance of ending up in any group. This equal probability helps prevent selection bias and distributes both known and unknown confounding factors across groups, making comparisons between groups more valid. It isn’t about guaranteeing exact equal numbers in every group, though that can happen by chance, nor is it about investigator preference, which would introduce bias. Allocation being blinded or not is a separate issue from how subjects are assigned; randomization can be done with blinding or without it.